A sealing concept of this type for a roller bearing has already been disclosed by JP 2003-227521 A1. FIGS. 1 and 2 of this prior publication show a groove ball bearing, in the outer ring of which a sealing washer is inserted in a circumferential annular groove. This sealing washer comprises a metallic reinforcement which is encapsulated with an elastic sealing material by injection moulding. At the end which faces away from the outer ring, this sealing washer has an elastic support part, from which two sealing lips branch off. Moreover, the sealing washer is provided with a further third sealing lip, all three sealing lips interacting with an undercut which is arranged in the inner ring. The undercut in the inner ring is of asymmetrical configuration, with the result that the inner ring has two shoulders with different diameters; firstly, a first shoulder which adjoins the raceway region directly, and secondly a second shoulder which delimits the inner ring at its axial end and has a diameter which is smaller than the diameter of the first shoulder. The three sealing lips interact with the undercut in such a way that a rubbing seal and two gap seals are realized. The rubbing seal is formed by the first sealing lip which bears against a wall of the undercut. The first gap seal is formed by the second, axially outwardly directed sealing lip which covers the shoulder which lies on the outside of the bearing inner ring, at a spacing. Finally, the second gap seal is formed by the third radially inwardly pointing sealing lip, which covers the first shoulder of the bearing inner ring which adjoins the raceway region, at a spacing.
A disadvantage of this sealing concept is, in particular, that the support part with the first two sealing lips is inclined inwards in the non-installed state, the inclination being measured against a plane which extends at right angles to the rotational axis. This inclination ensures that, in the installed state, the first sealing lip bears against the side wall of the undercut in the bearing inner ring with pretension. This has the consequence that increased friction is attained with an increasing rotational speed as a result of the constantly large pressing force of the first sealing lip against the inner wall of the undercut, which increased friction is associated with impermissibly high friction heat. This can lead to the bearing temperature being increased in an impermissible manner, which can lead to a loss of lubricant which has a direct effect on the service life of the roller bearing.